A man, after skinning a dead animal, developed a pustule on his hand. A smear prepared from the lesion showed the presence of Gram positive bacilli in long chains which were positive for McFadyean's reaction. The most likely aetiological agent is-(

Ans. is 'c' i.e., Bacillus anthracis . Mc Fadyean's reaction is used for the presumptive diagnosis of anthrax. . History of skinning a dead animal, development of pustule, the presence of gram (+)ve bacilli in long chains with positive Mc Fadyean's reaction are suggestive of "anthrax" caused by Bacillus anthracis.